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$k$% WIDTH=16 HEIGHT=24 -th moment

\includegraphics[height=10mm]{images/moment}% WIDTH=48 HEIGHT=45

The operator can be placed on the canvas in two ways:

Returns the $k$% WIDTH=16 HEIGHT=24 -th moment about the mean along a named dimension of all elements present. $k$% WIDTH=16 HEIGHT=24 is specified by the numerical argument of the operation, which defaults to 1 (hence the result will be 0 in that case). If the dimension is not named, then the $k$% WIDTH=16 HEIGHT=24 -th moment is over all elements present in the tensor. Note that missing elements are not counted.

\begin{displaymath}
\langle\Delta x^{k}\rangle=\frac{1}{N}\sum_{i}(x_{i}-\langle x\rangle)^{k}
\end{displaymath}% WIDTH=377 HEIGHT=85

Also \begin{displaymath}
\sigma^{2}=\frac{N}{N-1}\langle\Delta x^{2}\rangle
\end{displaymath}% WIDTH=259 HEIGHT=68